Brake for manually operated rotary file

ABSTRACT

A circular file is rotatably mounted on a base that includes an annular electromagnet secured against rotation but movable toward and away from the base of the file. The magnet may be electrically energized via one or more switches positioned at various locations around the file in order to cause the electromagnet to frictionally engage and stop rotation of the file at any desired position.

1 ted States Patent [1 1 Loyd, Jr. 1 Sept. 4, 1973 1 BRAKE FOR MANUALLYOPERATED 917,594 4/1909 Hake 40/686 ROTARY FILE 1,695,322 12/19282,562,788 7/1951 [75] inventor: Samuel Aston Loyd, Jr., 2 750 051 /195Waynesboro, Va. 7 3,148,751 9/1964 White 188/164 [73] Assignee: AcmeVisible Records, linc., Crozet,

Primary ExammerDuane A. Reger Att0rney-Lee J. Gary, Russell W. Pyle etal. [22] Filed: Dec. 14, 1971 [21] Appl. No.: 207,892 [57] ABSTRACT Acircular file is rotatably mounted on a base that in- [52] 0.5. CI.188/164, 40/684 dudes an annular electmmagnet secured against rota- [51]11m. C1. F16d 65/34 tion but movable toward and y from the base Ofthe[58] Field of Search 40/68, 68.4, 68.6; We The agnet may be electricallyenergized via one 188/ 164; 312/183, 136 or more switches positioned atvarious locations around the tile in order to cause the electromagnet to[56] References Cited frictionally engage and stop rotation of the fileat any UNITED STATES PATENTS desired P 632,649 9/1899 Goldberg 40/684 5Claims, 6 Drawing Figures 68 60 flfi' I I 64 1 76 1 I I i 1 lll 76 745llll 7 l l i \P l 1 TE: Q4 42 1 1 {0 k; if 55 5 f: v? I ln\ I III-\Da/ II! 1.44.4.4 t W g 1 l I f f 3 (l l l 1 g l l l1 f as; wu r". i

PAIENTEDSEP um I 3.756356 SHEEI 2 BF 3 M. Hm. "HIP BRAKE FOR MANUALLYOPERATED ROTARY FILE BACKGROUND OF THE INVENTION This invention relatesto a rotary filing system and more particularly to an apparatus adaptedto carry large volumes of indexed filing data, which are retrievable bya plurality of persons located at control stations spaced around theapparatus.

A typical rotary filing system includes a wheel member which isrotatable about a vertical axis, with the wheel being adapted to carry amultiplicity of spaced indexing or divider elements that contain filedata such as cards, books and the like. Rotary filing systems areexpecially suitable and convenient for the handling of large volumes ofreference data within a relatively confined space by one or severalpeople stationed at fixed locations around the outer periphery of thewheel. The wheel is simply rotated until the desired information isreached, and the wheel is then stopped to allow access to theinformation.

As described in U.S. Pat. Nos. 3,056,506, 3,084,007, 3,120,824,3,124,398 and 3,383,147, the wheel of the filing system may be rotatablymounted on a base and driven by a motor. Stopping of the rotating wheeldriven by a motor presents no difficulties, since the continuousengagement of the motor drive with the wheel provides a braking effectwhen the motor is shut down.

In contrast to the aforesaid driven systems, the present invention isparticularly suitable for use with a manually rotated file that isrotatably mounted on bearings on a support. Because the circularfile maybe substantially great in diameter and may carry considerable weight,the inertia developed by the rotating file may be of such a magnitudethat stopping of the file at a precise location is difficult orimpossible. Thus, although the wheel may be easily rotated by hand, theproblem of accurately stopping the wheel has presented a deterrent tothe widespread use of such manually operated systems.

SUMMARY OF THE INVENTION The foregoing problems are solved by theprovision of an electromagnetic brake positioned between the wheel andits support. Preferably, the wheel is mounted on a vertical shaftextending upwardly from the support. An annular electromagnet is mountedon the top of the support around the shaft and has a pole facing upward.The electromagnet is mounted so as to be nonrotatable but movable towardand away from a metallic base plate on the wheel. A variable rectifiedDC circuit is provided to activate the electromagnet from a plurality ofstations by means of a switch located at each station. The annularelectromagnet, upon activation, frictionally engage the metallic baseplate on the wheel and immediately brings the wheel to a complete stop.Upon deactivation, the magnet immediately falls away from the base plateto allow unrestricted rotation of the wheel. The power through theelectromagnet may be varied to increase or decrease the degree ofbraking force applied on the wheel.

THE DRAWINGS FIG. l is a perspective view, shown partly in outline, of arotary file assembly, the wheel thereof being dissociated from the base;

FIG. 2 is an enlarged fragmentary perspective view of the base of theassembly, looking downward from the top thereof and illustratingfeatures of the presently described invention;

FIG. 3 is a vertical sectional view of the rotary file assembly thatincorporates features of the presently described invention, with thewheel of said assembly being omitted for the sake of clarity;

FIG. 4 is a plan view of the base of the assembly, taken substantiallyalong line 4-4 of FIG. 3;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 3; and

FIG. 6 is a schematic of the circuit employed in connection with thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. l, the rotaryfiling system generally comprises a circular file wheel 10 adapted tocarry file data in any suitable manner well known to those skilled inthe art. Thus, the wheel 10 may comprise a discshaped base 12 having aplurality of upstanding and radially arranged partitions 14 at the outerperiphery thereof between which books or other articles of data may bestored. The wheel 10 is adapted to be rotatably mounted around avertical shaft 16 secured in an underlying base 18 and extendingupwardly therefrom.

As shown in FIGS. 1, 2 and 3, the base 18 supports the wheel 10 andincludes a rectangular unitary framework comprising four vertical legs20 having respective threadably adjustable feet 22 to permit leveling ofthe base. Respective pairs of transverse beams 24 and 25 are securedbetween the respective tops and an inter mediate portion of opposedpairs of legs 20. In addition, respective upper and lower pairs ofclosely spaced cross beams 26 and 28 are secured medially between thetransverse beams 24 to complete the basic framework. The framework maybe surrounded by a cylindrical enclosure 30 which extends slightly abovethe level of the internal framework.

As best shown in FIGS. 2, 3 and 5, the lower portion of the shaft 16 issupported centrally within the base between the pairs of cross beams 26and 28. The bottom of the shaft 16 is received in a socket 32 mountedupon a base plate 34 secured at its corners (FIG. 5) by bolts 36 or thelike to and between the lower pair of cross beams 28, in order tostabilize the lower end of the shaft and to vertically secure the shaftat a fixed level. The socket 32 may include a set screw 38 engaging andpreventing rotation of the shaft. The shaft 16 is also held in positionat the top of the framework by means of a top plate 40 secured at itscorners (FIG. 4) to and between the upper cross beams 26 by means ofbolts 42 or the like, said top plate having a circular aperture 44 thatsnugly receives and supports an intermediate portion of the shaft.

The file wheel or tier 10 is freely rotatably mounted on the shaft 16 ina fixed vertical position above the base 18. A central vertical opening46 is provided in the bottom of the wheel and is fitted with a collar 48surrounding the upper portion of the shaft 16 and spaced therefrom. Thecollar 48 has a downwardly facing shoulder 50 abutting the outer race 52of a bearing 54 extending from the collar and secured around the shaft.The outer race 52 is supported upon a large discshaped base plate 56secured centrally to the bottom surface of the wheel base 12 and havinga central aperture 58 therein for accommodating the shaft 16. A sleeve60 is provided around the shaft 18 and extends between the top plate 40and the inner race 62 of the bearing 54, thereby maintaining avertically fixed distance relationship between the top plate 40 of thebase and the base plate 56 of the wheel.

The brake assembly, as best shown in FIGS. 2 and 3 generally includes anelectromagnetic member 64 secured in the base against rotation butmovable vertically into and out of frictional engagement with the baseof the wheel to provide the required braking ef feet. The electromagnet64 is preferably annular in shape and contains a coil connected betweenleads 66 and 68 (FIG. 2) and embedded in magnetizable material betweenrespective inner and outer concentric upstanding bands 70 and 72 mountedon an annular base 74 (FIG. 2). The electromagnet is thus designed tohave an upwardly facing pole face that may be attracted to the baseplate 40 of the wheel, said base plate being formed of a ferrous orother magnetic material.

As shown in FIGS. 2 and 4, the electromagnet 64 is normally supported ontop of the plate 40 and is retained thereon by means of two or moreopposed upstanding studs 76 received in respective aligned apertures 78in the annular base 74 of said electromagnet. In this manner, theelectromagnet 64 is movable axially or vertically toward and away fromthe stationary plate 40 on the studs 76 but is positively restrainedagainst rotation about its vertical axis or against other movement byvirtue of said studs. Upon activation, the elec' tromagnet 64 movesupward by its magnetic attraction toward the base plate 56 of the wheeland thereby frictionally engages said base plate to quickly retardrotary movement of the wheel.

FIG. 6 illustrates a schematic of a circuit which may be employed tocontrollably energize the magnet and which utilizes 115 V AC current. Aconventional bridge rectifier 80 is connected in series to the AC line82 which may include a fuse 84. The rectifier, utilizing foursemi-conducting devices, supplies full wave rectified current betweenthe leads 66 and 68 of the electromagnet 64 which are connected at thepositive and negative sides of the rectifier.

A control circuit is also provided in the AC line to regulate thecurrent available to the rectifier 80. For this purpose, a bridge 86 isprovided in the AC line, one side of which is connected to the anode ofa triac or its equivalent, which is a bi-directional silicon thyristor88 capable of conducting current when switched from a high impedancestate to a low impedance state. The other side of the bridge 86comprises the gating circuit for the triac and contains a variableresistor 90 and a charging capacitor 92 connected in series and a diac94 connected between said resistor and capacitor to the gate of thetriac 88. The diac 94 is also a bi-directional component and serves tocontrollably switch the triac 88 to a conductive state when power isapplied in the circuit. The resistor 90 may thus be convenientlyadjusted to vary the power available to the coil of the electromagnet 64and hence to vary the degree of available braking force to be applied.

In order to close the circuit, a relay 96 is connected across the ACinput, an isolation coil is connected to a plurality of normally openpush button switches 98, which when closed, shorts out the remotecontrol winding and closes the main circuit. In this manner, one

switch may be provided at each of the various operator locations aroundthe wheel.

In operation, the wheel 10 is turned and rotated by one of a pluralityof operators desirous of locating a file. When the desired location isreached, the operator pushes a switch 98, which closes the main circuit,thereby energizing the electromagnet to perform the braking function. Aslong as the operator maintains the stop button in a closed position, thebrake remains in engagement and prevents rotation of the wheel by otheroperators. The variable resistor may be conveniently adjusted to controlthe braking force, depending on the weight and size of the wheel.

It will be apparent to those skilled in the art that variousmodifications and changes in design may be made to the inventiondescribed herein without departing from the scope of the appendedclaims.

Having thus described the invention, what is claimed 1. A rotary filecomprising a circular filing wheel, a base, a fixed vertical shaftsecured in said base and extending upwardly therefrom, bearing andsupport means between said filing wheel and said base for rotatablymounting said wheel around said shaft above said base at a substantiallyfixed vertical distance therefrom, a magnetic plate secured to thebottom of said wheel, support means secured in said base around saidshaft, a plurality of studs projecting upward from said support means,an annular electromagnet disposed around said shaft and normally restingon said support means, said electromagnet having apertures therein inwhich respective studs are received, whereby said electromagnet islimited in movement to a vertical direction toward and away from saidmagnetic plate, and means for providing electrical energy to saidelectromagnet to activate the same, said electromagnet, upon activation,being attracted to and frictionally engageable with said magnetic plate,such that friction between said electromagnet and said plate brakesrotary movement of said wheel.

2. The rotary file of claim 1 wherein said means for providingelectrical energy to said electromagnet comprises an electrical circuitconnected thereto, and a plurality of switches connected in parallel insaid circuit, said switches being provided at spaced locations aroundsaid wheel to allow braking of said wheel from each of said locations.

3. The rotary file of claim 2 wherein control means are provided insaidcircuit for regulating current through said electromagnet, said controlmeans comprising a triac connected in said series in said circuit, asource of voltage connected to the gate of said triac, and means forregulating the voltage to said gate.

4. A rotary file comprising a filing wheel, a base beneath said wheel,means for rotatably mounting said wheel over said base, brake meanssupported upon said base and movable into engagement with said wheel,said brake means comprising an electromagnet having an upwardly facingpole face and means on said base for confining movement of saidelectromagnet to a direction toward and away from said wheel, a platecomposed of a magnetic material is mounted on the bottom of said wheeland is engageable by said electromagnet, and means for energizing saidelectromagnet from various positions around said wheel.

5. The rotary file of claim 4 whprein means are provided for adjustingthe flow of current through said electromagnet for regulating the degreeof braking force applied thereby.

1. A rotary file comprising a circular filing wheel, a base, a fixedvertical shaft secured in said base and extending upwardly therefRom,bearing and support means between said filing wheel and said base forrotatably mounting said wheel around said shaft above said base at asubstantially fixed vertical distance therefrom, a magnetic platesecured to the bottom of said wheel, support means secured in said basearound said shaft, a plurality of studs projecting upward from saidsupport means, an annular electromagnet disposed around said shaft andnormally resting on said support means, said electromagnet havingapertures therein in which respective studs are received, whereby saidelectromagnet is limited in movement to a vertical direction toward andaway from said magnetic plate, and means for providing electrical energyto said electromagnet to activate the same, said electromagnet, uponactivation, being attracted to and frictionally engageable with saidmagnetic plate, such that friction between said electromagnet and saidplate brakes rotary movement of said wheel.
 2. The rotary file of claim1 wherein said means for providing electrical energy to saidelectromagnet comprises an electrical circuit connected thereto, and aplurality of switches connected in parallel in said circuit, saidswitches being provided at spaced locations around said wheel to allowbraking of said wheel from each of said locations.
 3. The rotary file ofclaim 2 wherein control means are provided in said circuit forregulating current through said electromagnet, said control meanscomprising a triac connected in said series in said circuit, a source ofvoltage connected to the gate of said triac, and means for regulatingthe voltage to said gate.
 4. A rotary file comprising a filing wheel, abase beneath said wheel, means for rotatably mounting said wheel oversaid base, brake means supported upon said base and movable intoengagement with said wheel, said brake means comprising an electromagnethaving an upwardly facing pole face and means on said base for confiningmovement of said electromagnet to a direction toward and away from saidwheel, a plate composed of a magnetic material is mounted on the bottomof said wheel and is engageable by said electromagnet, and means forenergizing said electromagnet from various positions around said wheel.5. The rotary file of claim 4 whprein means are provided for adjustingthe flow of current through said electromagnet for regulating the degreeof braking force applied thereby.